Hybrid Characteristics of Heterogeneous Traffic Flow Under Different Aggregating Lane-Change Strategies in Intelligent Network

In order to study the evolution rule of heterogeneous traffic flow under the background of IOV （internet of vehicles）, the concept of relative entropy in introduced to quantitatively describe the orderliness of heterogeneous flow, and analyze the inner link among orderliness, market penetration rate of CAV （connected and autonomous vehicle）and the number of queues for CACC (cooperative adaptive cruise control). Then, it is deduced that the increase on the market penetration rate of CAV and decrease on the number of queues can improve the orderliness of heterogeneous flow. Second, two improved lane change strategies for CAVs are proposed, namely, conservative aggregation (CSA) and radical aggregation (RDA). Through the simulation test of cellular automata, the advantages and disadvantages of no aggregation (NOA), conventional aggregation (CVA), CSA, and RDA are compared in terms of traffic capacity, relative entropy and average queue length. Finally, the effect of different limits of minimum queue size on traffic capacity is analyzed with the lane change strategy of CSA. The results show that the use of lane change strategy can prompt the CACC collaborative queue in CAV and orderly heterogeneous flow. It improves traffic capacity in the density range from 20 to 95 veh/km. Compared with the NOA strategy, the CSA strategy increases the traffic capacity by 12.6%, and the RDA strategy by 14.0%. However, when the market penetration rate of CAV is 0.8, the maximum traffic capacity of the RDA strategy is reduced by 25.8%. According to the quantitative description of relative entropy for the aggregation degree of CAV in heterogeneous flow, four lane change strategies (NOA, CVA, CSA and RDA) increases the aggregation degree of CAV in turn. In the CSA strategy, when the minimum queue size of CACC takes 4 vehicles, the efficiency of traffic capacity is the optimal.